JP2661226B2 - Power supply for vehicles - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply apparatus for a vehicle in which a power supply for a load that requires a high-voltage power supply mounted on the vehicle is set.

[Prior Art] An electric load usually mounted on a vehicle such as an automobile, for example, a control electric and electric load, a headlight, etc., is configured by a low voltage load corresponding to a generated voltage of a battery mounted on the vehicle. Is done.

However, in recent years, a transparent metal thin film has been vapor-deposited on a window glass for automobiles, and an electric current is applied to the metal thin film to generate heat, thereby heating the window glass and deicing ice or frost attached to the glass in a short time. It is thought to be. It is a necessary condition that the metal thin film used here is transparent, and in particular, it is configured to be thin, and its resistance value is set to, for example, 4Ω. Further, in a state where ice adheres to the window glass, it is required that the ice be thawed in a short time, so that the electric power supplied to the metal thin film reaches, for example, 1500 W. Therefore, the power source of this metal thin film is 77
A high voltage of V is required, and a power supply of the required voltage cannot be formed by using a vehicle-mounted generator and a battery that are usually mounted on a vehicle as they are.

That is, the voltage required here is much higher than the voltage generated by the battery, and in order to constitute such a required voltage power supply, for example, Japanese Patent Application Laid-Open No. 55-1782
As disclosed in JP-A-46-46, it has been considered that a voltage generated by a battery is boosted by a transformer and used.

However, there is no need to supply power except for the above-described thin metal film for thawing the window glass and the thawing period, and during the period when this thawing function is not activated, the step-up transformer is not used. Function is completely unnecessary. This transformer not only occupies the volume in the engine room, but also increases the vehicle weight.

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and in a case where a load using a high-voltage power supply is mounted on an automobile, a high-voltage power supply is applied to the load. In the case where such a high-voltage power supply is set, the high-voltage power supply can be appropriately used as a low-voltage power supply, and a charging device for a battery is included. It is an object of the present invention to provide a power supply device for a vehicle which can be reduced in weight.

[Means for Solving the Problems] In a power supply device for a vehicle according to the present invention, a generator for generating high voltage is set together with a generator for generating low voltage. A voltage regulator in which a first voltage adjustment value corresponding to a battery charging voltage and a high voltage second voltage adjustment value suitable for a high voltage load are set, wherein the first voltage adjustment value is the low voltage The voltage is set to a value lower than the voltage adjustment value of the voltage generator and higher than the minimum chargeable voltage of the battery.

[Operation] That is, in the vehicle power supply device configured as described above, the voltage regulator set in the high-voltage generator is:
When the high voltage load is operating, the second voltage adjustment value is set, and when the high voltage load is not operating, the first voltage adjustment value is selected and set. Then, in a state where the power consumption of the vehicle increases and the capacity of the low-voltage generator is insufficient,
The power generated by the high-voltage generator can be used for charging a battery. Therefore, the low-voltage generator can be configured with a reduced capacity, and even in a vehicle equipped with a high-voltage load, it is easy to reduce the weight of a power supply unit including a power supply for the load. Can be planned.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows, for example, the configuration of a power supply device mounted on an automobile. This vehicle is mounted on an ordinary automobile or the like, and is supplied with electric power from a battery 11 mounted on the vehicle. Further, a low-voltage load 12 such as a headlight and a high-voltage load 13 made of a metal thin film for heating a glass formed by the above-described vapor deposition of window glass or the like are mounted and set. The low-voltage load 12 is supplied with power from the battery 11.

On the other hand, in this device, a low-voltage generator 14 and a high-voltage generator 15 are provided. This generator 14 and 15
Are driven by an in-vehicle engine (not shown), the low-voltage generator 14 includes a first voltage regulator 16,
The voltage regulator 16 detects the voltage V _B of the battery 11 to adjust the generated voltage Vact1 low voltage generator 14.

Further, the high-voltage generator 15 includes a second voltage regulator 17. The voltage regulator 17 selects and detects one of the terminal voltage V _B of the battery 11 and the one-phase terminal voltage of the stator coil corresponding to the output voltage Vact2 of the high-voltage generator 15 by the changeover switch 18. Then, with the switch 18 set to the terminal a on the side of the battery 11, the battery 11
, The output voltage of the high-voltage generator 15 is lower than the output voltage Vact1 of the low-voltage generator 14, and
A low voltage value Vlo between the lowest chargeable voltage of 1
Set and control to w. When the switch 18 is turned on to the terminal b for detecting the terminal voltage of the high-voltage generator 15, the output voltage of the high-voltage generator 15 is set to the high voltage value Vhigh required by the high-voltage load 13. I do.

The voltage generated from the high-voltage generator 15 is supplied to a changeover switch 19 that is interlocked with the changeover switch 18, and when the switch 19 is connected to the terminal a, the voltage generated from the high-voltage generator 15 is Electric power is supplied to the battery 11.
When the switch 19 is turned on at the terminal b, the output voltage of the high-voltage generator 15 is supplied to the high-voltage load 13 and the load 13 is activated.

That is, the switch 19 is turned on to the terminal b when the high-voltage load 13 is activated. In this state, the voltage generated by the high-voltage generator 15 is supplied to the load 13 and, for example, the window glass Is heated to remove ice, frost and the like attached to the glass. in this case,
The switch 18 is also set to the terminal b, and the high-voltage generator 15 is set to generate the high voltage Vhigh.

FIG. 2 shows a specific example of the first voltage regulator 14 of the low-voltage generator 14. The terminal 161 is connected to the battery 11, and the terminal voltage of the battery 11 is supplied. Also terminal
162 is connected to the field coil 141 of the rotor of the low-voltage generator 14, and terminal 163 is connected to ground. Then, in response to the voltage V _B of the battery 11 by controlling the field current of the low voltage generator 14, adapted to the low voltage load 12 in the generator 14, and voltage compatible Vact1 the charging voltage of the battery 11 is generated I am trying to be.

FIG. 3 shows a specific example of the second voltage regulator 17 set in the high-voltage generator 15, and a changeover switch 1 is connected to a terminal 171.
Eight movable terminals are connected to a voltage detection terminal. The terminal 172 is connected to the field coil 151 of the rotor of the high-voltage generator 15, the terminal 173 is grounded, and the breakdown voltage of the Zener diode 174 and the diode 175
Utilizing both temperature characteristics of the forward voltage drop, the generated voltage Vact2 of the high-voltage generator 15 is kept constant corresponding to the voltage from the terminal 171 irrespective of the temperature.

That is, in this power supply device, the switch 19 is operated to supply the output power from the high-voltage generator 15 to the high-voltage load 13 when ice, frost, or the like adheres to the window glass in winter. In this case, the changeover switch 18
Is also operated, and the voltage generated from the high-voltage generator 15 is supplied to the second voltage regulator 17 via a rectifier or the like. Then, the high-voltage generator 15 generates the high voltage Vhigh and supplies it to the high-voltage load 13.

On the other hand, for example, in a state where ice or the like does not adhere to the window glass and the high voltage load 13 does not need to be operated, the switches 18 and 19 are turned on to the terminal b as shown in FIG. The terminal voltage of the battery 11 is supplied to the second voltage regulator 17 as a detection voltage, and the output voltage of the high-voltage generator 15 is set to be supplied to the battery 11 via the switch 18. Therefore, the second voltage regulator 17 detects the terminal voltage of the battery 11, and the high-voltage generator 15 generates the low voltage Vlow.

Here, since the output voltage Vlow of the high-voltage generator 15 is set to be lower than the output voltage Vact1 of the low-voltage generator 14, when the low-voltage load 12 is small,
Charging of the battery 11 is adjusted by the output voltage Vact1 of the low-voltage generator 14. The generated power from the high-voltage generator 15 is not used, and there is almost no power consumption due to the driving force for the generator 15.

However, the low voltage load 12 has increased and this low voltage generator 14
When the battery 11 cannot be charged with the output voltage from the battery 11, the voltage of the battery 11 decreases. And
When the voltage V _B of the battery 11 is lower than the adjusted value Vlow of the low voltage side of the second voltage regulator 17, high voltage generator 15
Starts power generation, supplies the generated power to the low-voltage load 12, and charges the battery 11.

Due to an increase in the electric load of an electric fan and the like due to the use of FFs in automobiles and a reduction in the size of the engine room, the temperature in the engine room tends to increase. In such a state, the charge balance of the battery 11 deteriorates in summer when the engine room becomes particularly hot, and in order to deal with this, the low-voltage generator 14 tends to have a larger capacity and a larger size. is there. In such a situation, the high-voltage load 13 for heating the window glass and the like is not used in summer when the temperature is high, and the high-voltage generator 15 is used in a state where it performs its own function. There is no opportunity to do it.

However, in the power supply device shown in the above embodiment, when the low-voltage load 12 is increased as described above, the output voltage from the high-voltage generator 15 is used for the low-voltage load 12 and the battery 11 Used for charging. That is, the high-voltage generator 15 is used as an auxiliary to the low-voltage generator 14.

Therefore, the low-voltage generator 14 is in a state in which the low-voltage load 12 is increased, the capacity of the conventional low-voltage generator 14 may be sufficient, and the low-voltage generator 14 can be further downsized.

When the high-voltage load 13 is a resistor such as a metal thin film adhered to window glass, a slight voltage fluctuation can be tolerated in the power supplied to the load 13.
For this reason, when adjusting the high voltage generation state in the second voltage regulator 17, the voltage can be detected and used from one phase of the stator of the high voltage generator 15, and the voltage regulator and the generator can be used. The change due to the increase in the voltage may be small, which is advantageous in cost.

In the embodiment, the first voltage regulator 16 of the low-voltage generator 14 is used.
The temperature characteristic is set to the adjustment voltage value Vact1. Therefore, when the temperature state changes, the power generation operation can be performed in the best state. On the other hand, in the second voltage regulator 17 of the high-voltage generator 15, the switch 18 is connected to the terminal a to detect the voltage of the battery 11 connected to the adjustment voltage value Vlow.
Is constant regardless of temperature. Therefore, even when the temperature conditions of both the low-voltage and high-voltage generators 14 and 15 become different, the adjustment voltage Vlow of the high-voltage generator 15 is always the adjustment voltage value of the low-voltage generator 14. Vact
It can be set lower than 1, and the high-voltage generator 15 is effectively used as an auxiliary for the low-voltage generator 14.

In the above embodiment, the changeover switch 19 has been described as being driven by manual switching.
The switch from the terminal b on the high voltage load 13 side to the terminal a on the battery 11 side is performed after the switch 19 is controlled to be switched to the terminal b side, and after a lapse of a predetermined time sufficient for the window glass to be thawed. You may make it perform automatically. If the high-voltage load 13 is used to heat glass, such as a heated windshield, the temperature of this glass is detected by a sensor, and if the glass temperature rises above a specified set temperature, For example, the switch 19 may be configured to be automatically switched from the terminal b to the terminal a. Also, when the voltage of the battery 11 is Vlow
When the following state occurs, this can be detected and the switch 19 can be preferentially connected and set to the terminal a side.

[Effect of the Invention] As described above, according to the power supply device for a vehicle according to the present invention, a high-voltage generator is specially set for a high-voltage load. Can be used as a supplement to a low-voltage generator for power generation, and can be effectively used when the low-voltage generation capacity is insufficient. That is, it is possible to cope with the increase in the electric load capacity without particularly increasing the capacity of the low-voltage generator and without increasing the size thereof, and to exert a great effect for reducing the size and weight as a whole. become.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a power supply device for a vehicle according to an embodiment of the present invention, and FIGS. 2 and 3 are specific diagrams of the first and second voltage regulators in the above embodiment, respectively. It is a circuit diagram showing an example. 11… Battery, 12… Low voltage load, 13… High voltage load, 14… Low voltage generator, 15… High voltage generator, 16, 17
... First and second voltage regulators, 18, 19...

Claims (2)

(57) [Claims] An on-board battery for supplying power to a low-voltage load mounted on a vehicle, and the battery for generating a voltage corresponding to the low-voltage load and supplying charging power to the battery A low-voltage generator provided with a voltage regulator for setting a voltage adjustment value corresponding to the charging operation of the vehicle, supplying power to a high-voltage load mounted on the vehicle, and a voltage regulator of the low-voltage generator. A first voltage adjustment value set lower than a set voltage adjustment value and higher than a minimum voltage capable of charging the battery, and a voltage regulator set with a second voltage adjustment value corresponding to the high voltage load A high-voltage generator comprising: a high-voltage generator comprising: a high-voltage generator having a high-voltage load; Generator power The adjustment voltage value of the voltage regulator is set to the second voltage adjustment value, and the adjustment voltage of the voltage regulator of the high-voltage generator is adjusted to the second voltage value in a state where the switch means does not select the high-voltage load. A power supply device for a vehicle, wherein the power supply device is set to an adjusted voltage value of 1 and power generated from a high-voltage generator is supplied to the battery. 2. A patent wherein the second voltage adjustment value of the voltage regulator set in the high-voltage generator is set based on the voltage of a one-phase terminal of a stator coil of the high-voltage generator. The power supply device for a vehicle according to claim 1.